1. Technical Field
This invention generally relates to an Electric Loop Wire Bindery Press for closing open-looped book binding wires, and more particularly to a bindery press which utilizes a unidirectional electric motor and pitman arm assembly to actuate the pressing mechanism.
2. Background
Open wire binding presents a number of advantages over spiral binding as a means of fastening paper for books, tablets and other uses. With open wire bindings, the pages turn more freely and are not hindered by the wire binding. Additionally, open wired binding allows greater flexibility in the amount of paper to be fastened, as the site of the wire element can be adjusted to accommodate varying amounts of paper.
In open wire binding, the pages to be bound are first punched in a die punch which perforates the pages to form either square or rectangular holes, usually at the frequency of either two or three holes to the inch. The pages are then inserted over the wire tracks of the open wire element. The open wire element, which is open in "C" shaped fashion, is then inserted in to a mechanical press, wherein an elongated platen is used to apply uniform pressure to all of the tracks of the wire elements to close them to a circular shape, thus binding the pages to form the book.
In the prior art, the binding presses are either mechanically or electrically driven. In either configuration, the binding presses incorporate an elongated pressing platen bar, which must be held and moved parallel to a fixed plate to insure that all of the loops of the wire element are uniformly pressed to a preselected, closed, diameter. Fixed slide bar guides are typically used to hold the pressing platen bar in alignment as the platen is mechanically moved up and down. Additionally, the platen bar assembly is typically permanently attached to and in fixed adjustment to the pressing linkage assembly to insure that it remains in alignment and does not bind on the guide bars. With electric presses, the prior art configurations utilize a electric bidirectional motor, which turns in one direction to move the platen pressing bar towards the stationary plat, and in the other direction to retract the platen bar. Electronic controls are utilized in conjunction with the bidirectional electric motors to adjust the length of the throw of the platen bar for varying sizes of wire elements. The binding wire elements are commonly available and utilized in the size range, ranging from 3/16 of an inch to 1 inch in diameter when closed. Hence, the travel of the bidirectional electric motor must be adjustable over a comparable range to insure its adaptability for use with varying sizes of wire elements. This results in the incorporation of expensive bidirectional motors, control systems in electric binding presses.
A bindery press assembly that utilizes a unidirectional motor and a mechanical adjustment in lieu of an adjustment in platen bar throw, would greatly simplify the press and result in a corresponding reduction in its manufacturing costs.
Accordingly, it is the object of the present invention to provide a bindery press which utilizes a unidirectional electric motor for motive power in conjunction with a cam and pitman arm assembly to convert unidirectional drive shaft rotation to a reciprocating longitudinal pressing motion for an elongated platen bar. Another object of the present invention is the incorporation of a mechanical platen bar adjustment mechanism wherein the minimum spacing between the platen bar, and the fixed plate can be adjusted thus enabling utilization of the press over the full range of available wire elements diametric sizes.